'87 45hp merc - stalls

[btatum]

engine will go from full throttle to 1/4 to idle (without moving throttle) and then stall- after running for about 5 min. Have ck'd fuel filters, pumped fuel primer when running and engine will start to skip (stop pumping and skip will clear). finally located loss of spark, wait 10-15 min and engine will start and go about 75-100 yds and stall again. again loss of spark. ???<br />before engine will stall it will run fine then start to skip and rpms reduce (almost to idle speed) then stall. Wait a little & do it all over again.

 

[quig0090]

Re: '87 45hp merc - stalls

I had a similar problem. Our first guess was fuel, fuel line and filter. Then the next guess was plugs and stator. It was none of that. It was the ignition that caused the motor to cut off. We would run fine for about 30 seconds then it would cut off. Wait a while, it would start again but only for another few seconds. I don't know the motor schematics you have but this is how I found the problem. Disconnect the wiring harness at the motor. This is where the kill wire is located at my motor (Mercury bigfoot 60hp). Put a remote starter on the motor and a volt meter on it. Start it and watch the meter. My meter ran at 300 volts with the harness disconnected. As soon as I connected it while it was running the volts went down to 70 and then the motor turned off. We thought the entire wiring harness frrom the motor back to the console might need replacing but finally found it at the ignition. So we just need to replace the ignition. You might also want to check that there is not a short at the Lanyard switch also. This would prevent the motor from starting also. Hope that helps

 

[btatum]

Re: '87 45hp merc - stalls

thanks for the info, tried to ck the system but now it won't run at all. i was tring to ck wiring but it kind of hard when it won't run. the rectifier has 2 wires that lead to the stator do you know how to ck those? should i ck for voltage,ohms? the rectifier has battery voltage when i try to start the engine. there is a grey wire that leads from the rectifier to the ignition switch, is this a kill wire? if i remove it to ck system would it work? i am down to believing the switch box is the problem but i'm not sure.

 

[btatum]

Re: '87 45hp merc - stalls

more info, i tried to move wiring to see if it would spark while i spun it over to no avail.<br />also the stator was replaced about a year ago.